package info.guardianproject.util;
import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.os.AsyncTask;
import android.os.Build;
import android.widget.LinearLayout;
import java.lang.ref.WeakReference;
public class BackgroundBitmapLoaderTask extends AsyncTask<Integer, Void, Bitmap> {
private final Resources resources;
private final WeakReference<LinearLayout> linearLayoutReference;
public BackgroundBitmapLoaderTask(Context context, LinearLayout linearLayout) {
resources = context.getResources();
// Use a WeakReference to ensure the LinearLayout can be garbage collected
linearLayoutReference = new WeakReference<LinearLayout>(linearLayout);
}
private int calculateInSampleSize(BitmapFactory.Options options, int reqWidth,
int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
final int halfHeight = height / 2;
final int halfWidth = width / 2;
// Calculate the largest inSampleSize value that is a power of 2 and keeps both
// height and width larger than the requested height and width.
while ((halfHeight / inSampleSize) > reqHeight && (halfWidth / inSampleSize) > reqWidth) {
inSampleSize *= 2;
}
}
return inSampleSize;
}
private Bitmap decodeSampledBitmapFromResource(Resources res, int resId, int reqWidth,
int reqHeight) {
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeResource(res, resId, options);
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeResource(res, resId, options);
}
@Override
protected Bitmap doInBackground(Integer... resIds) {
return decodeSampledBitmapFromResource(resources, resIds[0], 100, 100);
}
// Once complete, see if LinearLayout is still around and set bitmap.
@SuppressWarnings("deprecation")
@SuppressLint("NewApi")
@Override
protected void onPostExecute(Bitmap bitmap) {
if (linearLayoutReference != null && bitmap != null) {
final LinearLayout linearLayout = linearLayoutReference.get();
if (linearLayout != null) {
if (Build.VERSION.SDK_INT >= 16)
linearLayout.setBackground(new BitmapDrawable(resources, bitmap));
else
linearLayout.setBackgroundDrawable(new BitmapDrawable(resources, bitmap));
}
}
}
}